A Long Island Chauffeurs daughter is desperately in love with the youngest son of the family her father works for. Sent away to Paris for two years (partly to learn how to cook, and partly to cure her infatuation), she returns with a sophisticated new look, and finds that he is now infatuated with her.
As is clear from the above outline, and from the very beginning of the film which starts with the line "Once upon a time there was a little girl...." this film is basically a fairy tale in which Hepburn's Cinderella gets to choose between the two sons of the fabulously wealthy Larrabee family. It features a wonderful cast - William Holden excels as the charming playboy David Larrabee (the original object of Sabrina's affections), and Bogart, somewhat cast against type as a romantic lead, shows a deft touch for comedy as older brother Linus, who attempts to disentangle his brother from Sabrina only to find himself falling for her too.
This is a tale which could easily become mawkish, but is kept from doing so by witty dialogue and wonderful physical comedy (Linus manipulating his brother into sitting down on a champagne glass, and then providing him with a hammock with a strategic hole cut out is my favourite, but there are many such moments). But this is Hepburn's film, and she is magnificent. Her transformation from gawky teenager to sophisticated young woman is entirely convincing, and she never looked lovelier.
Forget Pretty Woman, forget Maid in Manhatten, this film did it first and it did it better. Get a big bar of chocolate, unplug the phone, and sit back and enjoy the most beautiful face ever captured on film.